Safety device for sadirons



Jung 18, *1935i A. CARUTHERS, JR

SAFETY DEVICE FOR SADIRONS 'Filed July 19, 1933 2 INVENTO R fe cznzerzs 7;

` ATTORNEY;

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Patented June 18, 1935 UNITED STATES PATENT OFFICE SAFETY DEVICE FOR SADIRONS Abe Caruthers, Jr., Nashville, Tenn.

Application July 19, 1933, Serial No. 681,131

1 Claim.

This invention relates to a safety device for electric sad-irons and the like for breaking the electric circuit upon over-heating of thc iron, and an object is to provide means and an arrangement thereof for the purpose, which is positive in operation and not liable to get out of order in long use. A further object is to provide means whereby the device may be adjusted to operate at the desired temperature, to break the circuit, and to provide an arrangement and combination of parts especially adapted for embodiment in a sad-iron construction.

With the above and other ends in view, the invention consists in the matters hereinafter set forth and more particularly pointed out in the appended claim, reference being had to the accompanying drawing wherein;

Figure 1 is a side elevation, with portions broken away and in section, of a sad-iron illus- 20 trative of an embodiment of the present invention;

Fig. 2 is a top plan view of Figure l., partly broken away to show the safety device in place therein;

Fig. 3 is a rear end elevation of the iron;

Fig. 4 is a transverse section substantially upon the line 4-4 of Figure 1; and

Fig. 5 is an enlarged sectional detail, upon the line 5-5 of Figure 2.

The sad or flat iron comprises the usual sheet metal casing I for enclosing the usual heating unit, this casing being shaped to conform to the outline of the usual at, thick iron base 2 and is detachably secured thereto by lag screws 3 or the like, which screws are utilized to secure the usual handle 4 to the top of the casing.

The heating unit comprises a heavy metal block or body 5 spaced from the casing and resting upon the heating element 6 which consists of two spaced apart strips of mica or other suitable material upon which is wound a continuous flat wire to form two resistance coils with insulating sheets above and below said coils to electrically insulate said coils from the body 5 and base 2. 45 The terminal ends of this wire forming said coils,

are attached to terminal members I and 8, preferably formed of sheet metal to extend upwardly within a large notch or recess 9 formed in the rear end of the body 5 and opening through the top and end of said body, said recess being formed with a bottom wall I0 extending part way toward the rear open end of the recess to cover all but a small portion of the heating element at the rear open end of said recess, to provide for the attachment of said terminal members 'I and 8 to the ends or the coils, through notches or slots li in an insulating plate I2 secured within the recess 9 upon the bottom wall I3 thereof.

To close the open end of the recess 9 in the body 5, a plate i3 is secured at its ends by screws if! to the end of the body and this plate forms a support for a pair of contact members I5 and i6 in the form of short rods, the outer ends of which are curved downwardly and provided with contact ends l! of a metal different from that of 1'0 the rods, to contact suitable contacts on a suitable stand, not shown, and which contacts are connected within a power circuit in the usual manner to supply current through the members I5 and I6 to the heating element 6 when the sad 15 iron is placed upon said stand in proper position.

These contact members I5 and I6 extend inwardly through suitable slots in the casingl and through openings in the supporting plate I3, they being electrically insulated from said plate yby suitable insulation I8 and rigidly secured in place by means of jamb nuts I9 thereon. The terminal member I is secured directly to the inner end of the member I5 by a second jamb nut 2U, and the member I6 is formed at its inner end with a con- 25 tact head 2| to be directly contacted by a similar head 22 or end on a short bolt 23, the terminal member 8 being directly connected to said bolt 23 by being clamped between said head 22 and a block 24 sleeved on said bolt. 30

This bolt 23 is secured to and carried by the end of a laterally flexible strip member or contact carrier 25, said strip being formed with an opening near its free end, through which the bolt extends and a nut 26 on the end of the bolt clamps said strip between said block 24 and said nut 26, suitable insulating members 21 being provided to electrically insulate said bolt from said strip, which strip or carrier is supported from the supporting plate I3 at its end opposite that carrying the bolt 23, by a stud 2B and is supported intermediate its ends and nearer to its free end by an adjusting screw 29 secured at one end to said plate and screwthreaded at its inner end to pass through an opening in said strip with jamb nuts 3E) on said end engaging opposite sides of said strip. The said adjusting screw 29 is effectively concealed within the casing I against tampering.

Said flexible contact carrier comprises a plurality of strips, preferably two secured face to face and formed of dissimilar metals having different co-efiicients of expansion so that when subjected to a high temperature, one will expand more than the other, and, as the two strips are secured together, such unequal expansion will cause the strip, as a whole, to bend laterl fore if a Very hot sad iron is desirable, this adest coeicient of expansion being located at the,

side of the contact carrier 25, toward the said contact 2|. Therefore heating of said contact carrier by heat generated within the casing i will cause said carrier to bend laterally at its free end which carries the contact 22, and open the electric circuit by moving the said Contact 22 out of Contact with the contact 2 l.

The operation of said carrier .25 to open the circuit may be regulated by means of the screw 29 as by means of this screw, the carrier mayY be adjusted laterally to bring said contacts into engagement with greater or lesser force, and therefore if adjusted to hold said contacts in engagement with each other with considerable force, the higher will be the degree of heat necessary to bend the carrier suflciently to separate said contacts and break the circuit. Therejustmentis made so that the circuit will not be broken until the desired degree of heat is reached.

Due to the construction of this safety or cutout device, there is nothing to get out of order and the element or carrier which is affected by the heat, due to its construction, will function for the life of the flat iron in which it is ernbodied. Further the rdevice is simple in construction and occupies but little space, so that it may be effectively embodied in the iron by providing a chamber in the end of the body, which chamber may be left open to provide free circulation of the heat and to give free access tothe several parts and connections, the bending of the carrier being resisted but little by the connection of its contact With the heating coil, due to the arrangement and shape of the terminal member 8 which is formed With an upstanding yieldable end connected to said terminal and which terminal member is formed from a metal strip shaped adjacent said end to give free yielding action.

Obviously changesY may be made Vin the construction and arrangement within a sad iron, without departing from the spirit of the invention, and such changes are contemplated.

Having thus fully described my invention, what Ir claim is:

In a sad iron including a casing, and apair oi contact members extending through said casing and a heating element having one terminal connected to one of said contact members, and having the other terminal bent to form an upstanding flexible support, a thermostatic switch comprising a contact head connected to said ilexible support terminal of said heating element, a laterally flexible contact carrier carrying said contact head into and out of engagement with the other of said Contact members, said flexible Contact carrier being formed of strips of metal having different coefficients of expansion, means for xedly supporting said contact carrier at its opposite end, and a regulator controlling the temperature at which said switch operates, said regulator also supporting said contact carrier and being positioned on said carrier nearer to its free end than to its secured end.

ABE CARUTHERS, J R. 

